hulk inclusion
category: bugfix
bugzilla: 167379
CVE: NA

Reference: https://lore.kernel.org/linux-arm-kernel/20210610123556.171328-1-wangkefeng.wang@huawei.com/

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When user code execution with privilege mode, it will lead to
infinite loop in the page fault handler if ARM_LPAE enabled,

The issue could be reproduced with
  "echo EXEC_USERSPACE > /sys/kernel/debug/provoke-crash/DIRECT"

As Permission fault shows in ARM spec,
  IFSR format when using the Short-descriptor translation table format
    Permission fault:       01101 First level      01111 Second level
  IFSR format when using the Long-descriptor translation table format
    Permission fault:       0011LL LL bits indicate levelb.

Add is_permission_fault() function to check permission fault and die
if permission fault occurred under instruction fault in do_page_fault().

Fixes: 1d4d3715 ("ARM: 8235/1: Support for the PXN CPU feature on ARMv7")
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>